In an Olympic final of unremitting tension and ferocious competition Rebecca Adlington lost her 400m freestyle title – but still won a bronze medal behind Allison Schmitt and the victorious and hugely impressive Camille Muffat. Bill Furniss, Adlington's coach, had always predicted that the race would "turn into a dogfight". In his blunt and forthright way Furniss had also described Adlington, whom he has coached since she was 12, as "the ultimate racer".

Swimming in front of a roaring home crowd, the 23-year-old from Mansfield strove to turn those words into a defining truth as she attempted to become the first British swimmer in 104 years, since Henry Taylor in 1908, to complete a successful defence in the Olympic pool. But the inevitable dogfight had just too much snap and bite at the front.

Muffat and Schmitt forced a fierce pace from the outset, which eventually resulted in an Olympic record, and Adlington never looked likely to beat either the American or the Frenchwoman. But she did produce an immense last 100m to clinch Britain's second medal of the Games.

Four years ago, in the equivalent race at the Beijing Olympics, Adlington was in fifth place as she made the final turn for home. Yet with an astonishing burst of speed she passed the three women closest to her and then hunted down Katie Hoff, the celebrated American, to achieve a victory that was almost shockingly unexpected.

The miraculous comeback did not happen again here but Adlington would not be denied a medal as she powered her way from sixth to third place – and held off a fierce surge by Lotte Friis, her old Danish rival in the 800m. They should meet again on Friday but Adlington is at her best in a race which is twice as long. On the evidence of this swim, and her world No1 ranking over 800m, Adlington is now a compelling favourite to win Britain's first gold medal in the 2012 pool.

Over 400m, however, the speed of Muffat and Schmitt was blistering. The morning heats had provided a measure of the challenge they posed. Swimming early, in heat three, Adlington went out hard and such was her dominance that the rest of the field wilted. Chased only by the distant figure of the US's Chloe Sutton, fifth fastest in the world this year, Adlington looked imperious. She slowed over the last 100m, conserving the best of herself for the final, and very nearly paid a heavy price. As each of the heats unfolded, with qualifying times rocketing, the final lap of the morning's last race suddenly conjured up the prospect of Adlington failing even to make the final. In the end she scraped in with the eighth fastest time.

Federica Pellegrini, the world champion, was another star reduced to looking up anxiously at the big screen after the heats. The Italian qualified seventh – meaning that she and Adlington swam the final in lanes one and eight.

Adlington's draw meant she was the last competitor to be introduced to the crowd. If the reaction from an increasingly noisy home support ratcheted up the fevered atmosphere, the delayed arrival of Adlington underlined the extent of her battle to overcome a clear disadvantage. She waved stoically to the crowd and then, having stripped down to her textile suit, coolly splashed water on to her face and over her gleaming red cap.

At last year's world championships in Shanghai, when she won silver behind Pellegrini, Adlington recovered from a poor qualifying session and overcame the difficulty of swimming in lane one. She and Pellegrini both beat Muffat convincingly in that 2011 final – but the woman from Nice has improved markedly and arrived at these Olympics as the most consistently fast 400m swimmer in the world this year.

Muffat was irresistible in winning here; but Adlington will now draw upon her admirable powers of recovery as she seeks to defend her remaining Olympic title. As such an imposing competitor over 800m Adlington should be difficult to beat – as long as she again displays the familiar resilience that was so evident on Sunday night.

In a career of both glory and tumult she has been tested before. And, for an essentially grounded woman, the nature of those examinations have been surprisingly severe.

After she won her two gold medals in Beijing in 2008 Adlington was swamped by fame and, problematically, scrutinised more for her ordinariness outside the pool than her landmark sporting achievements. Her breathless fascination with designer shoes and reality television, and her homespun Mansfield background, made many people warm to her as an unaffected teenager; but it also obscured the true depth of her ability and resolve.

The intensity of attention contributed to the loss of confidence she suffered a year later. Disappointment in the 800m at both the 2009 world and European championships shook Adlington. "Confidence is something that is so hard to gain and so easy to knock," she said then. "Losing shocked me. It became mental rather than physical – which is so much harder to overcome. When it's a mental problem, nobody can really help you apart from yourself."

She also suffered outside the pool – with the comedian Frankie Boyle's cruel jibes about Adlington's appearance encouraging still darker verbal abuse from the "trolls" she despises on Twitter. Yet Adlington claims that this adversity both in and out of the pool has strengthened her. "I'm glad I did go through all those low points," she let on earlier this year. "It definitely made me tougher and more determined."

Her competitive steel was graphic during the brutal conclusion to this 400m final. It will surely rise to the surface again in the coming days as Adlington prepares to turn a bronze medal into gold by winning the 800m title she believes should belong only to her. Fittingly the first person she embraced after leaving the pool was Furniss. He looked prouder than ever to coach a racer as brave as Becky Adlington.